what is the meaning of the --max-flow-ctl

Can someone explain the meaning of the --max-flow-ctl parameter, do not understand how this percentage is calculated

My understanding is that A = $ (when spent on flow control (from the start of pt-osc/pt-archiver) / start executing pt-osc/pt-archiver to the current total duration * 100)
Pt-osc/pt-archiver is suspended when A > —max-flow-ctl specifies the value. Over time, when A < —max-flow-ctl specifies the value, continue to execute pt-osc/pt -archiver
I don’t know if it’s right

Can someone answer my question?

Hi Fan - this setting in pt-archiver ensures that the archiving routine doesn’t overwhelm a PXC cluster by setting a limit to how far replication can lag other members of the cluster.

From the documentation:

And background on PXC Flow Control:
What is flow control?

I hope this helps!

First of all, I want to express my gratitude, but this does not answer my question very well…
I want to know the algorithm of this parameter


The part of the code checking the lag/flow control is here:


thanks a lot !